Line follower with counter

Hi i just need help how to build a line follower robot micro controller based and also it must have a "7-segment display" to count the 4 black color blocks being put outside the track so that as the robot passes its block just like a tollbooth concept. When the robot encounter a block from either right or left section of the track if will feed a input to the display to count up. Also my 2nd problem i don't have any idea how to make the robot faster after it detects the first block then as he approaches the 2nd block he will reduced speed then accelerate after he passes the 2nd block until it will fully complete the track because there is a time limit set of each track....any idea is a big help for me..

This is my first time doing this project...

microcontroller can easily do it, but you need to add another sensor for detecting marks before, on and after every block.